Power density effects on the growth of microcrystalline silicon–carbon alloys by PECVD

Abstract

Hydrogenated microcrystalline silicon–carbon films (μc-SiC:H) have been grown in a plasma enhanced chemical vapor deposition system in low power regime, by silane+methane gas mixtures highly diluted in hydrogen. The effects of RF power density on the film properties and on the amorphous to crystalline phase transition have been investigated. The increase of the RF power density causes the decrease of the crystallinity degree and crystallite grain size and an increment in carbon incorporation. XRD analysis shows that μc-SiC:H alloys with higher dark conductivity (>10 −2 Ω −1 cm −1) contain silicon and carbon (3R graphite) crystallites, having average grain size of 200 Å, embedded in an amorphous silicon–carbon matrix. In low power regime μc-SiC:H films can be grown at low substrate temperature (200 °C).